PROPAGATION, the multiplication of a species by natural processes of reproduction. The Latin propagare meant to fasten down (pro- and pangere, to fasten) layers, shoots or slips (propagines) of plants for the purpose of reproduction, hence to generate, reproduce and generally to extend or increase. It is in this sense that "propagation" is used of the spreading or dissemination of doctrines, ideas, opinions, &c. The term "propaganda," often wrongly used as a plural word, means properly an organization or association for the spreading of particular beliefs or opinions, and is an adaptation of the name of that committee of cardinals in the Roman curia which supervises foreign missions, the full title being Congregatio de propaganda fide.